update secondary latency collector
update secondary latency collector

Change-Id: I78f989b7201b1c434507dfcc8185eb1059037832
Reviewed-on: http://review.couchbase.org/51584
Reviewed-by: Venu Uppalapati <5c73d43f38c8de2bc4a2e4d15365e52f60b59dae@gmail.com>
Tested-by: Venu Uppalapati <5c73d43f38c8de2bc4a2e4d15365e52f60b59dae@gmail.com>

mikewied/cbagent,couchbase/cbagent